The present invention relates to a device for adjusting the degree of vacuum in an apparatus for collecting substances by suction.
It is known that apparatuses adapted to aspirate various substances, particularly liquids, are used especially in the medical field: this is the case, for example, of apparatuses for collecting blood from drainages of the wounds of a patient in order to provide postoperative autotransfusion.
These apparatuses, which comprise a portion of space designed to be placed under low pressure or vacuum and connected by means of a duct to the sources of the liquid to be aspirated, are provided with a device for adjusting the degree of vacuum, which is provided according to various constructive embodiments, such as for example the one disclosed in Italian patent application MN00A000009 by the same Applicant.